中国物理B ›› 2021, Vol. 30 ›› Issue (6): 68201-068201.doi: 10.1088/1674-1056/abd7d2

• • 上一篇    下一篇

Morphologies of a spherical bimodal polyelectrolyte brush induced by polydispersity and solvent selectivity

Qing-Hai Hao(郝清海) and Jie Cheng(成洁)   

  1. College of Science, Civil Aviation University of China, Tianjin 300300, China
  • 收稿日期:2020-11-17 修回日期:2020-12-23 接受日期:2021-01-04 出版日期:2021-05-18 发布日期:2021-05-18
  • 通讯作者: Qing-Hai Hao E-mail:qhhao@cauc.edu.cn
  • 基金资助:
    Project supported by the Fundamental Research Funds for the Central Universities of China (Grant No. 3122020080).

Morphologies of a spherical bimodal polyelectrolyte brush induced by polydispersity and solvent selectivity

Qing-Hai Hao(郝清海) and Jie Cheng(成洁)   

  1. College of Science, Civil Aviation University of China, Tianjin 300300, China
  • Received:2020-11-17 Revised:2020-12-23 Accepted:2021-01-04 Online:2021-05-18 Published:2021-05-18
  • Contact: Qing-Hai Hao E-mail:qhhao@cauc.edu.cn
  • Supported by:
    Project supported by the Fundamental Research Funds for the Central Universities of China (Grant No. 3122020080).

摘要: It is commonly realized that polydispersity may significantly affect the surface modification properties of polymer brush systems. In light of this, we systematically study morphologies of bidisperse polyelectrolyte brush grafted onto a spherical nanocolloid in the presence of trivalent counterions using molecular dynamics simulations. Via varying polydispersity, grafting density, and solvent selectivity, the effects of electrostatic correlation and excluded volume are focused, and rich phase behaviors of binary mixed polyelectrolyte brush are predicted, including a variety of pinned-patch morphologies at low grafting density and micelle-like structures at high grafting density. To pinpoint the mechanism of surface structure formation, the shape factor of two species of polyelectrolyte chains and the pair correlation function between monomers from different polyelectrolyte ligands are analyzed carefully. Also, electrostatic correlations, manifested as the bridging through trivalent counterions, are examined by identifying four states of trivalent counterions. Our simulation results may be useful for designing smart stimuli-responsive materials based on mixed polyelectrolyte coated surfaces.

关键词: surface morphologies, polydisperse polyelectrolyte brush, solvent selectivity, molecular dynamics simulation

Abstract: It is commonly realized that polydispersity may significantly affect the surface modification properties of polymer brush systems. In light of this, we systematically study morphologies of bidisperse polyelectrolyte brush grafted onto a spherical nanocolloid in the presence of trivalent counterions using molecular dynamics simulations. Via varying polydispersity, grafting density, and solvent selectivity, the effects of electrostatic correlation and excluded volume are focused, and rich phase behaviors of binary mixed polyelectrolyte brush are predicted, including a variety of pinned-patch morphologies at low grafting density and micelle-like structures at high grafting density. To pinpoint the mechanism of surface structure formation, the shape factor of two species of polyelectrolyte chains and the pair correlation function between monomers from different polyelectrolyte ligands are analyzed carefully. Also, electrostatic correlations, manifested as the bridging through trivalent counterions, are examined by identifying four states of trivalent counterions. Our simulation results may be useful for designing smart stimuli-responsive materials based on mixed polyelectrolyte coated surfaces.

Key words: surface morphologies, polydisperse polyelectrolyte brush, solvent selectivity, molecular dynamics simulation

中图分类号:  (Polyelectrolytes)

  • 82.35.Rs
31.15.at (Molecule transport characteristics; molecular dynamics; electronic structure of polymers) 64.75.Va (Phase separation and segregation in polymer blends/polymeric solutions) 64.75.Yz (Self-assembly)